Klemczak Barbara, Goldmann Eryk, Gołaszewska Małgorzata, Górski Marcin
Department of Structural Engineering, Faculty of Civil Engineering, Silesian University of Technology, 44-100 Gliwice, Poland.
Department of Building Processes and Building Physics, Faculty of Civil Engineering, Silesian University of Technology, 44-100 Gliwice, Poland.
Materials (Basel). 2023 Nov 20;16(22):7246. doi: 10.3390/ma16227246.
This study aimed to investigate the heat generated during the hydration process in cementitious composites containing multi-walled carbon nanotubes (MWCNTs). The cumulative heat release and heat flow of these cementitious composites were measured over a period of 168 h using isothermal calorimetry. Three different MWCNT dosages, 0.05 wt%, 0.1 wt%, and 0.2 wt%, along with two different sonication times for the solution, which were 20 min and 60 min, were applied in the experimental program. The results reveal that the incorporation of MWCNTs and the use of a naphthalene-based superplasticizer to disperse the nanotubes generally led to a reduction in heat emission during the early stages of hydration, a lower first peak value in the initial stage of hydration, and a significant delay in the acceleration period compared with the reference sample lacking this superplasticizer. Furthermore, the results demonstrate that both the dosage of multi-walled carbon nanotubes (MWCNTs) and the sonication time have an impact on the heat emission and hydration process since the same amount of superplasticizer was applied to all pastes. An increase in the MWCNT dosage led to a decrease in the rate of hydration heat at the main peak for all pastes. Additionally, longer sonication times resulted in lower values of heat generated, reduced main peak values in the heat rate evolution, and generally extended delays in the occurrence of the main peak.
本研究旨在探究含多壁碳纳米管（MWCNTs）的水泥基复合材料在水化过程中产生的热量。使用等温量热法在168小时内测量了这些水泥基复合材料的累积热释放和热流。实验方案中采用了三种不同的MWCNT用量，即0.05 wt%、0.1 wt%和0.2 wt%，以及两种不同的溶液超声处理时间，分别为20分钟和60分钟。结果表明，与未添加该高效减水剂的参比样品相比，加入MWCNTs以及使用萘系高效减水剂来分散纳米管，通常会导致水化早期的热量释放减少、水化初始阶段的第一个峰值降低，以及加速期显著延迟。此外，结果表明，由于所有浆料都使用了相同量的高效减水剂，多壁碳纳米管（MWCNTs）的用量和超声处理时间都会对热量释放和水化过程产生影响。MWCNT用量的增加导致所有浆料主峰值处的水化热速率降低。此外，更长的超声处理时间导致产生的热量值更低、热速率演变中的主峰值降低，并且通常会使主峰值出现的延迟时间延长。
